Japan’s National Waste Management Organization (NUMO) has initiated the first stage of an assessment to determine whether Minamitorishima, a remote island in the Ogasawara chain, could serve as a long-term disposal site for radioactive nuclear waste.

The process begins with a literature review of geological studies, maps, and academic research focusing on seismic activity, fault lines, and volcanic risks in and around the island.

This initial phase is expected to last around two years and represents the earliest step in a multi-stage evaluation process for deep geological disposal facilities, which would require burying radioactive waste at depths of at least 300 meters for up to 100,000 years.

Minamitorishima, Japan’s easternmost island and located roughly 2,000 kilometers from Tokyo, has no permanent civilian population and is managed as part of Ogasawara Village.

The mayor has approved participation in the survey, making it only the fourth site in Japan to enter this evaluation stage, alongside Suttsu and Kamoenai in Hokkaido and Genkai in Saga Prefecture.

While local municipalities have agreed to the literature review stage, prefectural governors in Hokkaido and Saga have expressed opposition to advancing to the next phase, which would involve preliminary on-site surveys.

The project is part of Japan’s broader effort to identify long-term storage solutions for nuclear waste as spent fuel pools at many reactors approach capacity limits.

Reports indicate that storage pools at 17 nuclear plants were approximately 78% full at the end of last year, while plans for recycling fuel at the Rokkasho Reprocessing Plant remain delayed.

The central government has encouraged participation by offering financial incentives of up to 2 billion yen for municipalities that agree to initial studies.

NUMO has emphasized that final disposal of radioactive waste is a national responsibility and aims to expand the number of candidate areas under consideration.